New scopes should be mechanically centered, but that isn't always the case. To center the reticle, place a mirror against the objective lense, look thru the scope and you should see 2 pairs of reticles, although somewhat dimly. Adjust the windage and elevation turrets so you can only see one set of X hairs, in other words, so they are lined up with each other. One set you are seeing is the actual X-hair, the other is a reflection in the mirror. These are Luepold's instructions and it works on almost all scopes with a few exceptions. If you still have a zero problem, you'll probalbly need to change your mounting system